Repeater circuit breaker



Aug. 22, 1933.

J. P. MEDLIN 1,923,323

REPEATER CIRCUIT BREAKER 1 Filed Aug. 9, 1930 3 Sheets-Sheet 1 J E? M AM 7 Aug. 22,1933. J, E'D 1,923,323

REPEATER C IRCUI T BREAKER -Filed Aug. 9, 1930 3 Sheets-Sheet 2 Aug. 22,1933. J. P. MEDLIN REPEATER CIRCUIT BREAKER Filed Aug. 9, 1930 3Sheets-Sheet 3 bar-d gwuwdoz:

Patented Aug. 22, 1933 UNITED STATES BEPEATER omcurr BREAKER John P.Medlin, Great Falls, Mont., assignor to Railway & Industrial EngineeringCompany, Greensburg, Pa., a Corporation of Pennsylvania ApplicationAugust 9, 1930. Serial No. 474,204

12 Claims. (Cl. 200 -126) This invention relates to a circuit breakerand particularly to a repeating circuit breaker actuated by an explosivefuse.

In the art of clearing high tension electric circuits of overloads bybreaking the circuit, it has been .desired to have. a circuit breakerwhich is simple and inexpensive to manufacture, but which is certain andrapid in operation whereby the circuit may be opened in the leastpossible time after the occurrence of the overload. Circuit breakershaving a sufficiently rapid operation have heretofore been constructedbut they have been complicated in structure and consequently veryexpensive to manufacture.

One of the objects of the present invention is to provide a circuitbreaker which will be readily responsive to an overload in a circuit andwhich will break the circuit very quickly after such overload occurs.

Another object of the invention is to provide a circuit breaker of thequick-acting type which will be simple, rugged, and inexpensive'tomanufacture.

Another object of the invention is the provision of a circuit breakeractuated by an explosive fuse and provided with a repeating fuse holdercarrying a plurality of fuses whereby the circuit may be opened aplurality of times without the necessity for manually resetting orreplacing any members.

Still another objectof the invention is the provision of a repeatingcircuit breaker wherein is provided a time-delay mechanism forpreventing the reclosing of the circuit for predetermined time after theopening thereof.

Inthe drawings: F r

Fig. 1 is a side elevational view, partly in crosssection, showing thecircuit breaker;

Fig. 2 is an end elevational view; partly in crosssection of the samestructure;

Fig. 3 is a detail view partly in cross-section showing the actuatingmechanism;

Fig. 4' is a view of a section taken along line '4--4 of Fig. 3;

Figs. 5 and 6 are views taken along line 5-5 and 6-6, respectively ofFig. 1; and

Figs. '7 to 10 are fragmentary views showing details.

The circuit breaker is mounted on a base-plate 1 formed of insulatingmaterial, such as phenolic condensate, which base-plate is secured tothe top of an insulator 2, carried on a supporting frame 3. Secured onthe top surface of the base-plate is a cup-shaped base 4 of brass, orsimilar material, 55 in which is inserted the lower end of an oil-filledtank 5 constructed of insulating material, the top of which is closed bya brass cap 6 similar to the base 4.

The cap 6 carries a guide frame comprising a top plate '7, a bottomplate 8, a plurality of parallel side members 9 extending between thecircumferential portions of the top and bottom plates and a plurality ofparallel guide rods 10 extending between the plates '7 and 8. A secondinsulator 11 mounted on the supporting frame 3, carries a strap 12 whichis secured to certain of the side members9, intermediate their ends,thus providing means for securing the upper end of the circuit breakerstructure. The strap 12 also serves as a terminal member to which oneside 7 of the line may be connected.

Secured to the base 1, inside of the oil tank 5 is a pair of. opposedcontact springs forming a switch jaw 13. A movable switch blade 14,dieposed axially in said oil tank 5, depends from a head 15 arranged toreciprocate vertically in the guide rods 10. The lower end of the blade14 is arranged to move into contact with the jaw 13, and to be engagedthereby.

Cooperating with the head 15, is a. push rod 16 which extends parallelto and along the outside of the oil tank 5. The push rod 16 is securedby nieans of a pivot to an operating lever 17 which is itself pivotallysupported in a fulcrum member 18 mounted on the base-plate 1, andnormallyurged in a clockwise direction by aspring 1'7.

-A revolver, which forms one of the principal elements of the actuatingmeans, comprises ahollow pillar 19 upon which a fuse cylinder 20 ismounted for rotation in a horizontal plane. The fuse cylinder 20 is inthe form of a short cylindrical block having a plurality of chambers 21extending axially therethrough and equally spaced circumferentially ofthe block. A coiled spring 22 having one end anchored to the pillar 19andthe other end attached to the fuse cylinder 20 is disposed within thepillar 19 for the purpose of rotating the cylinder 20. Disposed in eachof the chambers 21 is an explosive cartridge fuse 23 of a type generallysimilar to that shown and described in detail in my copendingapplication, Serial Number 370,709, filed June 13, 1929. Each fuse 23comprises a cas- 105 ing 24 in which is disposed a projectile 25 and anignition wire 26, surrounded by an explosive material 27. A recoil disk28, disposed .over the ends of the fuses 23 to prevent them from movingupwardly when discharged, is secured in place by no a wing nut threadedon a bolt extending from the base of the pillar 19. The recoil disk 2&3may be readily removed for replacement of ex ploded fuses.

Disposed beneath the fuse block coaxial with each chamber is a hollowmetallic projectile cyl inder 29 insulated from the block by aninsulating washer 30. The lower end or" the fuse casing 24 is disposedin the cylinder and the projectile 25 extends downwardly from thecylinder 29 to such an extent that, when the chamber is directly abovethe free end of the operating lever, the end of the projectile 25 bearsagainst the side flange 31 of the lever 17 whereby rotation of the blockSzll is prevented.

soft metal brush 32 is supported on the base.

nal member and is arranged e wall of the block 25. A similar brns. ed asecond terminal 35, is arranged to bear against that projectile cylinder29 which directly ae the free end of the l7, and a resilient per 36 iscarried by the projectile cylinder 29 contacts with the projectile 25.econd j 37 connects the second terminal with t tank. base The head 15,shown in det in Figs. 9 and it, carried at the upper end of tile switchblade 14, is substantially rectangular in longitudinal crosssection andhas a portion of its lower, outer corner cut away to provide space for aguide 38 formed integral with the bottom plate, in which guide the pushrod reciprocates. lln impactsurface, or anvil 39 is formed on under sideof this cut away portion for cooperation with the upper end of the pushrod. A plurality or" lugs 40 on plate by a te' to agai the headcooperate slidably with the guide rods 10 to position the head 15 forreciprocation thereon. A flexible jumper 41 provides electricalconnection between the head 15 and the upper terminal 12.

The head 15 is provided with an opening 42 extending therethrough toform a loop 43 for cooperation with a time relay latch which is shown indetail in Figs. 7 and 8. Secured to a gear wheel 44 is an arm 45 whichis normally maintained in an upwardly inclined position by means of aspring 46 and which arm carries a pawl 47 arranged to move upwardly withrespect to the arm 45, but not downwardly. A. pinion 48 meshing with thegear wheel 44 is secured to'a second gear 49 which in turn drives a wormwheel 50. A worm 51, which meshes with the worm wheel, is carried by theupper end of a vertical governor shaft 52 upon which is mounted aflyball governor 53.

The device is well protected from moisture and dirt by means of aplurality of casings formed of insulating material. One casing 54surrounds the push rod. Mounted on the base-plate is another casing 55which covers the revolver and is provided with a portion fitted aroundthe lower portion of the oil tank 5. A third casing 56 surrounds theguide members and a fourth casing 57 is telescoped over the top end ofthe device to serve as a cover.

The electric circuit through the device may be traced as follows: Fromthe upper terminal 12 through the flexible jumper 41 to the head 15,thence through the switch blade '14 to the switch jaw 13 and the base 4,by way of the flexible jumper 37 to the inner terminal 35 and its brush34 to the projectile cylinder 29, thence by the flexible jumper 36 tothe projectile 25 and through the ignition wire 26 to the block 20, andfrom thence to the brush 32 carried by the outer terminal 33.

neareas The operation of the device is as follows:

Upon the passage of an excessive current through the circuit breaker theignition wire, in that fuse which is disposed above the free end of thelever 17, ignites and discharges the explosive which it contains. Theprojectile 25 is readily forced out of its cylinder 29 to move the freeend of the lever 17 downwardly. The end of the lever 17 which isconnected to the push rod 16 moves upwardly and pushes the rod ahead ofit. The upper end of the push rod it strikes against the anvil 39and'drives the head 15 upwardly.

The ascent of the head 15 carries the switch blade 14 upwardly to openthe circuit at the switch jaw 13. Inasmuch as the break in the circuitoccurs in the oil tank 5, the spark is quenched rapidly by the action ofthe oil.

The head 15 being freely slidable in the guide rods 10, moves upwardlypast the pawl 47 until it strikes the top of the casing where its energyoi momentum is expended. As the head 15 starts to move downwardly underthe actionof gravity, the pawl 47 enters the opening 42 in the head andengages the loop 43 to temporarily arrest further descent of the head15. The weight of the head 15 and blade 14 overcomes the tension of thespring 46 to move the lever arm 45 downwardly. The gear train is thusset in motion and the governor 53 is rotated. After a certain degree ofrotation the lever 45 becomes sufiiciently inclined to permit the head15 to be disengaged and descend to its lowermost position to reclose theswitch.

When the free end of the operating lever .17 is depressed by theprojectile 25, the cartridge block is permitted to rotate under theinfluence of thespring 22 to bring the next cartridge into position tobe engaged by the lever 17. The free end of the lever 17 is raised toits normal position by the spring 17' insufiicient time to engage thenext projectile thereby arresting further rotation of the cartridgeblock. Hence, the circuit breaker is automatically re-fused and thus,when the blade descends and is engaged by the jaws the circuit isreclosed. If the excessive current again passes through the circuitbreaker the cycle of operations .is repeated. It will be seen'that aslong as the overload remains on the line, the cycle of operations willbe repeated, until the cartridges have all been discharged. Where it isexpected that long overloads will occur, it will be necessary therefore,to provide enough cartridges, or to make the interval between successivecycles sumciently long, so that the switchopening mechanism will notfail to operate if the switch is reclosed While the overload is still onthe line.

Many uses of the invention will suggest themselves to persons skilled inthe art. One important use of the invention is its employment in alightning arrester system of the known type which includes a circuitbreaker and a spark gap in a circuit between a power line and ground.When a surge occurs due to the efiect of a lightning discharge, the gapbreaks down and permits current to flow to ground. However, if currentcontinues to flow, the fuse is discharged and the circuit breaker isactuated to open the circuit. The circuit breaker is automaticallyreclosed and if the excess voltage is no longer present, the currentwill not flow in the ground connection but if the excess voltage isstill present the circuit will again operate and will continue to do sountil the line is cleared/or until all; of the fuses have beendischarged.

I claim: 1. In a.circuit opening device, the combination with a set ofcooperating contacts, of means actuated by the passage of an electriccurrent through said device, for separating said contacts, said meanscomprising a projectile arranged to strike against a member connected toone of said contacts, and means for reestablishing engagement betweensaid contacts.

2. In a circuit opening device, the combination with a set ofcooperating contacts, of means for separating said contacts comprising aprojectile expelling fuse having its projectile arranged to strikeagainst a member connected to one of said contacts, and means activeupon the discharge of said fuse for resetting said separating means. 3.In a high tension circuit breaker, the combination with a stationarycontact member and a movable contact member, of means engaging saidmovable contact member and active upon the passage of an excessivecurrent through said circuit breaker, for moving said movable contactmember upwardly away from said stationary contact, guide means forreturning said movable contact member to its original position and meansfor delaying the descent of said movable contact member for apredetermined period of time.

4. The invention as set forth in claim 3, wherein said guide meansconstitutes a support for said delaying means.

5. The invention as set forth in claim 3, wherein said delaying meanscomprises a member lying in the path of movement of said movable contactmember and engageable thereby.

6. In a high tension circuit breaker, the combination with a stationarycontact member and a. movable contact member, of means cooperating withsaid movable contact member comprising a projectile dischargingcartridgefor separating said contacts, a second cartridge and means, actuated bythe discharge of said first cartridge, for substituting said secondcartridge in the place of said first cartridge in said separating means.

'7. In a high tension circuit breaker, the combination with a set ofswitch contacts, of a member carrying projectile expelling fuses,operating means for transmitting to one of said contacts the energy of aprojectile expelled from one of said fuses to move said contact *awayfrom-its cooperating contact and means actuated by the discharge of saidfuse for rotating said member to move another of said fuses intooperative relation with said operating means.

8. In a repeating circuit breaker for high tension circuits, a switchcomprising a set of cooperating contact members, operating means foropening said switch comprising a projectile expelling explosive fuseactuated by the flow of an excessive current through said. switch, asecond fuse, and resetting means, active upon the ex plosion of saidfirst fuse, for substituting said second fuse for said exploded fuse.

9. In a high tension circuit breaker, the combination with aself-recl'osing switch, of means for opening said switch including aplurality of explosive fuses, one of which is arranged inoperativeposition with relation to said switch, and

means, active upon the discharge of said operative fuse, for removingsaid discharged fuse and position.

10. In a high tension circuit breaker, the combination with a set ofswitch contact members, of operating means including an explosive fusefor separating said contact members, and means operative upon thedischarge of said explosive fuse for resetting said operating means.

11. The invention as set forth in claim 10, wherein said movable contactmember comprises a blade portion and a head portion and said operatingmeans comprises a push rod arrang to strike against said head portion.

1a. In a high tension circuit breaker, the com-, bination with astationary contact member and a movable contact member, of meansincluding an explosive cartridge disposed in cooperative relation withsaid movable contact member for separating said contacts, a second meansincluding a her to its position in engagement with said stationarycontact member.

. A JOHN P. MEDLIN.

